When my PC finally died a couple months ago i spent
HOURS on the ps3 browser lookin for a site that streams/downloads movies with the ps3 browser. The websites are hard to come by.
Then I found this:
http://www.ps3divx.net/
It works. Theres 2 sections: Streaming and Downloading. If you want to download the movie:
Put mouse on top of movie>Press Triangle>Save Target As>And let it go. You can download in the background just like you would shit from the store. I watched Hangover 2 on it and downloaded 5 or 6 movies with it.
No sports though.
Then i picked up a laptop. lol. Its cool when you have no computer and the ps3 is your last resort but its def not something id use daily.
Also, ps3 mediaserver is great. If you know how to extract audio on MKV's or mp4 files and convert the audio to AC3 5.1, then add it back into the video file the ps3 will read it just fine without PS3 Media Sever converting it.
I watch a lot of 1080p MKVs on it lol.